Enlarge / Don briefly reached hurricane status in July 2023. (credit: NOAA)

As July came to a close, the Atlantic Ocean was absolutely sizzling, particularly in areas where hurricanes commonly form.

In the "main development region," a stretch of tropical water between Africa and the Caribbean Sea where most major Atlantic hurricanes develop, the sea surface temperature averaged 82.4° Fahrenheit, a full degree above any previous July.

This kind of temperature, at least partly fueled by a changing climate, has only rarely been seen in past hurricane seasons—and then only during September or early October, when temperatures in the tropical Atlantic typically reach their peak.

Enlarge / A satellite image taken on Wednesday afternoon shows the "African wave train" out in force. (credit: NOAA)

To put it mildly, there are some extremely disturbing trends happening on planet Earth with its weather and climate right now.

For example, the thickness and extent of the Antarctic sea ice is off-the-charts low . Based on current measurements, taken near the winter solstice in the Southern Hemisphere, the sea ice extent is far below any previous year for which data is available, going back to 1981. The current extent is two standard deviations below the mean.

Closer to where I live, in Texas, the state is sweltering due to a dome of anomalously high pressure situated over northern Mexico and the southern part of the Lone Star State. This has been pushing temperatures to record highs across the state. On June 18, for example, the border town of Del Rio recorded a high of 111° Fahrenheit, smashing its old record for the day by 5°.

Enlarge / Hurricane Irma as seen by satellite in 2019. (credit: NOAA )

Congratulations, everyone—we've made it to the startline of the 2023 Atlantic hurricane season.

Fasten your seatbelts because it could be a wild and bumpy ride. Or maybe not. Because when it comes to tropical activity, no one can be sure what will happen more than a few days into the future. And after about 10 or 12 days? Chaos theory rules, baby.

Not everyone needs to read this article, but many of you do. According to the US Census, more than 60 million Americans live in coastal areas vulnerable to tropical systems in the Atlantic Ocean and Gulf of Mexico. For those residents, including yours truly, the threat of a tropical storm or hurricane lurks in the back of one's mind during the summer months like the dull pain of a past injury. The longer it has been since a nearby landfall, the more distant the hum. But it's there.

Enlarge / Hundreds of persons returning to their flood-wrecked homes in New Orleans after 1965's Hurricane Betsy. (credit: Bettman/Getty Images )

If you look back at the history of Atlantic hurricanes since the late 1800s, it might seem hurricane frequency is on the rise.

The year 2020 had the most tropical cyclones in the Atlantic, with 31, and 2021 had the third-highest , after 2005 . The past decade saw five of the six most destructive Atlantic hurricanes in modern history.

Then a year like 2022 comes along, with no major hurricane landfalls until Fiona and Ian struck in late September. The Atlantic hurricane season, which ends November 30, has had eight hurricanes and 14 named storms . It’s a reminder that small sample sizes can be misleading when assessing trends in hurricane behavior. There is so much natural variability in hurricane behavior year to year and even decade to decade that we need to look much further back in time for the real trends to come clear.

Enlarge / Hurricane Ian, as seen from the International Space Station. (credit: NASA)

The Atlantic hurricane season officially ends on Wednesday, bringing to a close the six-month period when the vast majority of tropical activity occurs in the Atlantic Ocean, Gulf of Mexico, and Caribbean Sea.

Prior to the season, forecasters generally expected a busier-than-normal season. However, six months later, overall activity this year has come in slightly below normal. One of the more scientifically rigorous measurements of seasonal activity—based on the length and intensity of storms—is Accumulated Cyclone Energy. This year's value, 95, is about three-quarters of the normal value of 126.

That bland statistic belies the fact that this was an odd season. After three weak early-season storms, the Atlantic basin produced zero named storms between July 3 and August 31. This was the first time since 1941 that the Atlantic had no named storm activity during this period. Then, a light came on. Four hurricanes formed in September, along with three more in November. This brought seasonal activity to near-normal levels.

Enlarge / A satellite image of Hurricane Ian as of 7:50 am ET on Wednesday. (credit: NOAA)

I have lived near the Texas coast for two decades and written about hurricanes professionally for nearly as long. When you do that, you think a lot about what would become of your home should the worst happen.

Well, the worst is happening in Southwest Florida today.

Hurricane Ian has undergone a remarkable period of intensification during the last 24 hours. After crossing the western end of Cuba and knocking that island nation's power grid offline, Ian started to weaken a bit Tuesday following this brief interaction with land. It also underwent an "eyewall replacement cycle," in which the centermost bands of the storm contract and are replaced by a new ring of storms farther out. Often this process temporarily weakens a storm, but Ian was hardly fazed.

Enlarge / The Atlantic hurricane season peaks on September 10. (credit: NOAA)

To state the obvious: This has been an unorthodox Atlantic hurricane season.

Everyone from the US agency devoted to studying weather, oceans, and the atmosphere—the National Ocean and Atmospheric Administration—to the most highly regarded hurricane professionals predicted a season with above-normal to well above-normal activity.

For example, NOAA’s outlook for the 2022 Atlantic hurricane season, which runs from June 1 to November 30, predicted a 65 percent chance of an above-normal season, a 25 percent chance of a near-normal season and a 10 percent chance of a below-normal season. The primary factor behind these predictions was an expectation that La Niña would persist in the Pacific Ocean, leading to atmospheric conditions in the tropical Atlantic more favorable to storm formation and intensification. La Niña has persisted, but the storms still have not come in bunches.

Enlarge / Released in May, this was the NOAA forecast for Atlantic hurricane activity in 2022. (credit: NOAA)

Take a deep breath, everyone—the Atlantic hurricane season is one-third over. And there's some good news to report.

To date, the Atlantic has produced three named storms, Alex, Bonnie, and Colin. Historically, three named storms before the beginning of August would represent a busier-than-usual start to a season that officially lasts six months, from June 1 to November 30. But a simple storm count is a superficial measure of activity.

None of these storms has exceeded tropical storm strength, and they lasted only about a day. By other more revealing measures, the Atlantic is having a relatively slow start. At the beginning of August, an average year produces nearly nine days on which a tropical storm or hurricane has been active. This year, the number of "named storm days" is just 3.25. And by the measure of "accumulated cyclone energy," which accounts for both storm duration and intensity, the Atlantic basin is only producing about 30 percent of its normal activity.